Process for raising the resistance of zinc to tearing during rolling



Feb. 16, 1932. JORDAN 1,845,155

PROCESS FOR RAISING THE RESISTANCE OF ZINC TO TEARING DURLNG ROLLING Filed July 30, 1928 lnrenfor: JNJM Patented Feb. 1 1932 t 1,845,155

UNITED STATES PATENT OFFICE, v

FRANZ JORDAN, on WIOKEDE-RUHR, GERMANY Process For. musrivo' ran RESISTANCE or zmc 'ro lemme DURING RoLLIi'vG 'Application filed July 30, 1928, Serial No. 296,428, and ifi Germany June 15, 1928.

Hitherto the rolling of zinc sheet has' been in weight and about 50-100 m. m. thick and carried out in the heated condition and at a of suitable width and length are plated in temperature amounting to about 100150 C. known manner on one or both sides withan Nevertheless, in spite of this heating, zinc aluminium coating, the thickness of which is does not stand heavy rolling pressures since about 510% the thickness of the core'metal. 5 its power of resistance is only small and it The plating is efiected on arolling apparatus tea'rs easily'under heavy rolling pressures or to which the aluminium sheet is conducted splits at the edges on being rolled. from. endless rollers on to the zinc block Therefore, in order to reduce the amount which is to be rolled, and the sheet is united 10 of waste, only small rolling pressures are to the zinc by pressure of the rollers. The 55 employed at the present time and the blocks accompanying drawing shows the method by to be rolled are as thin and light in weight as which the plating is carried out. Aluminium possible. Then, when these blocks have been sheet 2 is supplied from rolls of the materolled down to'a thickness of a few milli1ne-' rial 3, and is united to the surface ofthe zinc ters, this preliminary product is cut and the blockj bypffiihg thereon by meansof the 61) further rolling of the sheets takes place in sorollers 4. The further rolling, of the plated called packets that is to'say about ten to blocks can then take place under heavy prestwenty plates are placed one on top of ansure in another suitable rolling-machine. other and these are rolled down further in a The aluminium coatiilg prevents the zinc bundle under low pressure. In order that block from tearing or from splitting to any :5 thickness of the sheet may be uniform the considerable egrtent at the edges. The capaposition 'of the separate plates must be bility of the zinc for being rolled and with changed at each rolling. This is termed standing tearing is moreover completely mixing in practice. changed owing to the coating, so that the It will be clear that the above described rolling process can take place without any rolling process must proceed relatively slowconsiderable tearing or splitting occurring.

ly, and that waste always occurs. Rolling It is also possible to roll out thin sheets of out of the material inband form has not been any width in band form, since the heavy successfully accomplished because the roller roller pressure automatically heats up the pressure as hereinbefore explained, may not zinc to the degree necessary for the rolling be sufliciently heavy. process.

The object of the present invention is to The aluminum coating also does not preovercome these disadvantages. vent the zinc sheet from being worked. For

The invention is based on the discovery example, if the .zinc is to be soft soldered, it

that a thin aluminium coating rolled on the .can easily be removed by scraping. On the zinc considerably increases the capability of other hand the resistance of the'zinc to chemithe zinc for being rolled, so that heavy roller cal or atmospheric attack is greatly increased pressures can then be employed. There. also by the aluminium coating. The new process results from this that the blocks to be rolled therefore not only lessens the'cost of manumay be of much thicker and heavier proporfacture of zinc sheets, but it can advantions than previously, which again must actageously be employed in all cases in which celerate and cheapen the process to a very the small resistance of the zinc to chemical 1 considerable extent. action has hitherto been an obstacle to the The process is carried out in the following employment of zinc sheets. manner. Zinc blocks of about 300-500. kg. 1 What I claim is z- Aprocess for raising the resistance of zinc to tearing during rolling consisting in applying thin aluminium strips by pressure to a comparatively thick core of zinc so'that the 5 aluminium strips completely cover the core on two opposite surfaces While the thickness thereof amounts to 510% of that of the core, subjecting these parts to a preliminary rolling process so as to effect a union thereof, and finally rolling out this combined material; into thin strips at high rolling pressures Without intermediate heating so as to prevent cracking of the zinc core.

In testimony whereof I have signed my name to this specification. r

FRANZ JORDAN. 

